PHYLOGENETIC RELATIONSHIPS OF THE AUSTRALIAN LEPTOPHLEBIIDAE K.J. Finlay1 and Y.J. Bae, 2 1 Department of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia 2 Department of Biology, Seoul Women’s University, Seoul 139-774, Korea Abstract The phylogeny of Australian Leptophlebiidae has not been studied in detail although previous research has indicated close relationships with the Neotropical fauna. Phylogenetic relationships of Australian Leptophlebiidae were examined using a cladistic analysis of 34 morphological characters and 21 genera. Character polarity was assessed by out-group comparison and then analysed with NONA (version 2). The three most parsimonious trees produced were used to construct a strict consensus tree. Relationships among the Australian fauna specify some monophyletic groups and unresolved terminals. This study elucidates some previously unknown relationships among the Australian fauna and indicates that the currently recognised genera of Leptophlebiidae in Australia require further definition. Comparison with hypotheses previously proposed for Australian Leptophlebiidae demonstrate partial agreement, recognizing ‘Meridialaris’ and ‘Atalonella’ clades (sensu Pescador and Peters 1980a) and support for a sister relationship between the burrowing genera Jappa and Ulmerophlebia. Cladistic characters are tabulated and discussed with illustrations. Examined taxa, materials and comprehensive bibliographic sources are provided. Key words: phylogeny, Australia, Leptophlebiidae, Ephemeroptera, mayflies, cladistics. Introduction The Leptophlebiidae, considered to be one of the most diverse mayfly families (Peters 1988), are distributed worldwide with over 100 genera, predominantly found in the Southern Hemisphere (Hubbard 1990). The monophyly of the Leptophlebiidae, within the superfamily Leptophlebioidea, is now well established (Landa and Soldán 1985, McCafferty 1991). However, phylogenetic relationships within the family have not been considered in total, due to the large number of species involved, but rather have been studied in smaller groups. These groups entail biogeographical regions such as the Southern and Eastern Hemisphere (Tsui and Peters 1975, Peters and Edmunds 1970); South America (Pescador and Peters 1980a), New Zealand (Towns and Peters 1979, 1996), New Caledonia (Peters et al. 1978; Peters and Peters 1979, 1981a, 1981b; Peters et al. 1990, 1994), Africa (Peters and Edmunds 1964) and 233 234 K. J. Finlay and Y. J. Bae Madagascar (Peters and Edmunds 1984) or genus level relations, e.g., Meridialaris and Massartellopsis (Pescador and Peters 1987), Miroculis (Savage and Peters 1983), Nousia (Pescador and Peters 1985), Penaphlebia (Pescador and Peters 1991), Thraulus (Grant 1985) and Ulmeritus (Domínguez 1995). Only two studies of the evolutionary relationships of Australian genera have previously been undertaken. As part of the analysis of the cool-adapted Leptophlebiid fauna of South America, Pescador and Peters (1980a) inferred affinities between South American and Australian taxa. Later, Christidis (2001) performed an analysis of the Australian Leptophlebiidae, focussing on one evolutionary branch described by Pescador and Peters (1980a), which included several Australian representatives. Herein we report the relationships between the Australian Leptophlebiid genera and compare and contrast the relationships of the Australian Leptophlebiid genera with hypotheses already proposed, namely the grouping of the Australian genera into five distinct evolutionary lineages based primarily on morphological similarity. Methods We examined representative species of the 19 known Australian genera, along with the South American subgenus Nousia (Nousia), for phylogenetic analysis. Taxa (n=21) and characters (n=34) were compiled (Appendix A). NONA version 2.0 (Goloboff 1993) was used to construct a cladogram using the tree bisection- reconnection command (mult*). A strict consensus tree (nelsen command) was constructed from the resulting most parsimonious trees. WinClada version 0.9.99i (beta) (Nixon 1999) was used to redraw the tree with the characters and character states mapped. We borrowed type species material from the Museum of Victoria (MV), the Australian National Insect Collection (ANIC), the Australian Museum in Sydney (AM), the Queensland Department of Primary Industries (QDPI), the Natural History Museum, London (NHM), the Swedish Museum of Natural History (SMNH) and the Florida Agricultural and Mechanical University collection (FAMU). Additional specimens were borrowed from the private collections of I.C. Campbell (Campbell collection) and P.J. Suter (Suter collection). We also had specimens from our personal collections (Finlay and Bae collections). Morphological characters and character states (Appendix B) were determined from examination of the specimens and from the species descriptions in the literature. Key sources of information for the ingroup genera included: Atalophlebia (Tillyard 1933; Suter 1986); Atalomicria (Campbell and Peters 1993), Austrophlebioides (Campbell and Suter 1988, Parnong and Campbell 1997), Bibulmena (Dean 1987), Garinjuga (Campbell and Suter 1988), Jappa (Skedros and Polhemus 1986, Bae and Finlay 2003, Bae et al. 2004), Kalbaybaria (Campbell 1993), Kaninga (Dean 2000), Kirrara (Campbell and Peters 1986), Koorrnonga (Campbell and Suter 1988), Loamaggalangta (Dean et al. 1999), Neboissophlebia (Dean 1988), Nousia (Pescador Australian Leptophlebiidae 235 and Peters 1980a; Campbell and Suter 1988), Nyungara (Dean 1987), Thraulophlebia (Demoulin 1955a, Campbell and Suter 1988), Thraulus (Grant 1985, Suter 1992), Tillyardophlebia (Dean 1997) and Ulmerophlebia (Suter 1986, Bae et al. 2004). In addition, the taxa Nousia (Australonousia) and Thraulophlebia were recently revised (Finlay 2002) leading to the synonymisation of Thraulophlebia with Koorrnonga over which it has priority (Finlay, Suter and Campbell, unpublished data) and the establishment of two new genera: ‘New Genus A’ and ‘New Genus B’ (Finlay, unpublished data). In agreement with Edmunds and Allen (1966), Riek (1973) and Pescador, and Peters (1980a), larval characters were found to be more taxonomically informative than those of the imago, hence the disproportionately low number of adult characters. Further, wing venation, one of the major characteristics of the adult, is known to be subject to significant parallel evolution (Edmunds 1972). Character polarities were assessed across all available outgroups (Watrous and Wheeler 1981). The nearest outgroup was the Leptophlebiinae, comprising eight genera (Paraleptophlebia, Leptophlebia, Habroleptoides, Habrophlebia, Calliarcys, Habrophlebioides, Dipterphlebioides, Gillesia) considered a primitive furcation in the evolution of the Eastern Hemisphere Leptophlebiidae (Peters and Edmunds 1970) and sufficiently different to warrant the establishment of a new subfamily (Peters 1980). Within this subfamily the plesiotypic Paraleptophlebia and Leptophlebia provided particularly valuable cladistic information. The latest revisions of the higher classification of mayflies (McCafferty 1991, McCafferty 2002), encompassing the work of Landa and Soldán (1985), provide the next nearest outgroups within the Infraorder Lanceolata: that of the sister group Ephemeroidea (Polymitarcyidae, Euthyplociidae, Potamanthidae, Ephemeridae, Palingeniidae) followed by the superfamily Caenoidea (Ephemerellidae, Tricorythidae and Caenidae). Although the superfamily Behningoidea (containing the single family Behningiidae) is considered more closely related to Leptophlebioidea (McCafferty 1991) than the previous two superfamilies, its use as an outgroup is limited due to its highly distinctive and specialized nature in both adult and nymphal forms (Edmunds 1959). Key literary sources of information for the outgroup taxa are as follows: Leptophlebiinae - Paraleptophlebia, Leptophlebia (Burks 1953, Peters and Edmunds 1970), Habroleptoides, Habrophlebia, Calliarcys, Habrophlebioides, Dipterphlebioides (Peters and Edmunds 1970), Gillesia (Gillies 1951, Peters and Edmunds 1970), Ephemeroidea - Ephemeridae: Aethephemera (McCafferty 1971a, McCafferty 1973), Afromera (Demoulin 1955b, McCafferty and Gillies 1979, Elouard 1986a), Eatonica (McCafferty 1971b, Elouard 1986b, Elouard et al. 1998), Ephemera (McCafferty 1973, McCafferty 1975, Hubbard 1982, Hubbard 1983; Balasubramanian et al. 1991, Kang and Yang 1994, Bae 1995, Ishiwata 1996), Hexagenia (Spieth 1941, McCafferty 1975, Keltner and McCafferty 1986), Ichthybotus (Eaton 1899), Litobrancha (Lestage 1939, McCafferty 1975), Euthyplociidae: Afroplocia (Demoulin 1952a), Campylocia (Demoulin 1952a, 236 K. J. Finlay and Y. J. Bae Pereira and Da Silva 1990), Euthyplocia (Lestage 1918, Lestage 1939, Demoulin 1952a), Exeuthyplocia (Lestage 1918, Lestage 1939, Gillies 1980), Proboscidoplocia (Demoulin 1966), Polyplocia (Demoulin 1952a), Mesoplocia (Demoulin 1952a); Palingeniidae: Cheirogenesia (McCafferty and Edmunds 1976, Sartori and Elouard 1999), Chankagenesia (Demoulin 1952b), Palingenia (Sartori 1992), Pentagenia (Lestage 1918, McCafferty 1972, McCafferty 1975, Keltner and McCafferty 1986); Polymitarcyidae: Campsurus (Eaton 1868-69, McCafferty 1975), Ephoron (Lestage 1918, Spieth 1933, Demoulin 1952a, McCafferty 1975, Ishiwata 1996), Tortopus (Needham and Murphy 1924, McCafferty 1975, McCafferty and Bloodgood 1989, Lugo-Ortiz and McCafferty 1996), Povilla (Lestage 1918; Lestage 1939; Hubbard 1984), Potamanthidae (Bae and McCafferty